1. Field of the Invention
The invention relates to methods and devices for the treatment of air of at least one room by air ionization wherein this ionization is realized by electrical discharge in ionization tubes or in corona discharge tubes.
2. Description of the Related Art
It is known that the room air and thus the breathing air can be treated with ionization apparatus. In this context, bacteria and other germs are killed and large molecules are split up into smaller molecule fragments. Complex and large molecules are, inter alia, odor-causing substances so that odor can be suppressed by means of air ionization. Moreover, it is even possible to eliminate room air loading situations which are detrimental to the health of persons in the room as well as to effectively reduce microorganisms in the air.
In ionization apparatus a high electrical field between two voltage potentials is used. For this purpose, as is known in the art, ionization tubes in the form of glass tubes are used in which the inner side is coaxially coated and the outer side is electrically conducting. When a sufficiently high electrical voltage is supplied, the glass of the wall forms a dielectric substance in which a large electrical field is present. The air flowing through is then enriched with ions. An important disadvantage is that starting at a certain voltage ozone is formed, and the ozone formation increases with increasing voltage.
In German patent document 43 34 956.0 C2 a method for the treatment of air with ions and a device for performing the method are described wherein the long-term stability of the ionization apparatus is increased. The discharge voltage is controlled such that the threshold for an increased ozone generation is never surpassed. As in the case of unloaded natural air, with the prior art method and the prior art device a minimum intensity of oxygen ions of approximately 5% as the lower process limit is technically maintained, and this corresponds substantially to the natural value. By means of the employed sensors, which are provided in the form of air-quality sensors, an airflow sensor, and an air humidity sensor, this minimum intensity within a load range can be substantially maintained.
When outer disturbance sources are present, i.e., an increased ozone loading in the ambient air, for example, in smog situations resulting from sun radiation, different situations in nature, for example, inverted weather situations, thunderstorms, outer energy fields, or in the case of inner disturbance sources, for example, in the form of electrical devices installed in the vicinity of air supply lines for transformation of voltage or frequencies, electromagnetic radiation, or other radiation, the loading with ozone in the supply air can increase undesirably and can lead to surpassing the limit value.
It is an object of the present invention to provide a method and a device for performing the method of the aforementioned kind such that a loading with ozone will not surpass a certain limit value.
In accordance with the present invention, this is achieved with respect to the method in that air ionization is carried out by means of electrical discharge in ionization tubes or in corona discharge tubes, wherein the level of ionization power is determined by an electronic control device as a function of the parameters:
oxidizable air components in the air to be treated,
relative air humidity in the air to be treated,
flow velocity or volume flow of the air to be treated,
ozone loading in the supplied air, and
minimum intensity of oxygen ions,
determined by sensors, i.e., a first air quality sensor, an airflow sensor, an air humidity sensor, an ozone sensor, and/or a second air-quality sensor.
In accordance with the present invention, this is achieved with respect to the device for performing the method according to the invention, wherein a supply line for supplying treated air is connected to at least one room to be supplied with treated air, in that a second air-quality sensor is provided in the room and/or in an exhaust line of the room and/or in the circulation line of the room between an exhaust line and the air treatment device, and in that the supply line between the air treatment device and the at least one room is provided with at least one ionization apparatus, an airflow sensor, and air humidity sensor, and an ozone sensor, and that the air-quality sensors, the airflow sensor, the air humidity sensor, and the ozone sensor are functionally connected via signal lines with the electronic control device.
The methods and devices for air treatment of at least one room by ionization, carried out by electrical discharge in ionization tubes or by corona discharge, are characterized, in particular, in that the level of ionization power is determined by an electronic control device depending on the values or parameters of the oxidizable air components (for example, vaporous organic compoundsxe2x80x94VOC), the relative humidity, the flow velocity/volume flow, the loading of the air to be treated by ozone, while ensuring a minimum intensity of positive and negative oxygen irons (matching the natural state of the air), which parameters or values are determined by sensors, i.e., a first air-quality sensor, an airflow sensor, and air humidity sensor, an ozone sensor and/or a second air-quality sensor. The method according to the invention is controlled such that, in particular, that the following values are determined directly: loading of the external air with volatile hydrocarbons by a first air quality sensor, the flow velocity or the volume flow of the air to be treated by an airflow sensor, the relative humidity of the air to be treated by an air humidity sensor, the contents of ozone in the supply air by an ozone sensor, and the oxidizable air components of the exhaust air and/or of the circulating air by means of a second air quality sensor in the circulation line between the room and the air treatment device or, optionally, in the exhaust line or, optionally, in the room. Corresponding to the above listed measurement values, the level of the ionization power of at least one or more ionization apparatus is controlled by the electronic control device such that the minimum intensity of oxygen ions is lowered and, when ozone values are too high, the ozone is reduced by formation of free radicals as well as natural oxygen clusters.
The special advantage resides in that, in particular, also the value of ozone in the supply air is correspondingly evaluated, controlled, and, when reaching or surpassing fixed points, signals are sent to the electronic control device. Accordingly, the ionization apparatus is affected such that a detrimental effect on persons present in the room is prevented as much as possible. This is the result of the ozone sensor provided in the supply line of the room and connected via the electronic control device to the ionization apparatus.
The electronic control device ensures an indeed stable supply air ionization which corresponds to natural levels wherein a predetermined ozone limit value is not surpassed and wherein, in extreme situations, ozone is eliminated. In this connection, the above indicated sensor signals are evaluated and processed in the control device such that optimized alternating pulses, which are supplied to the at least one ionization apparatus, automatically adjust a situation-specific ionization intensity. Each alternating pulse is a full sine curve which can be cut off when passing through zero, if needed. The frequency and voltage (potential) are not changed in this connection. Advantageously, in contrast to prior art solutions, several alternating pulses (several sine curves) are combined to packages or sets. The package size and thus the number of the alternating pulses of each package or set provides a possibility to further optimize the air ionization and to minimize at the same time loading of the electrical power mains. It is important in this connection that the discharge voltage remains constant so that a stable air ionization is ensured.
The solution according to the invention is characterized furthermore by ensuring a process safety and an increase of efficiency wherein also the safe application of air-technological devices with a directed use of air circulation is provided. In this connection, for high external temperatures in summer and low temperatures in winter, considerable energy savings for cooling or heating are realized. Further advantageous effects can be derived from reconstruction of already existing and the design of new air-technological devices. These are, inter alia, lowering of the proportion of external air, in particular, for a high degree of humidity in the external air or the increase of service life of the air filters.
The ionization of the supply air and optionally additionally of the circulating air results advantageously particularly in the decomposition of gaseous volatile hydrocarbons, in the lowering of the oxidation potential of the air, and the elimination of microorganisms.
A method according to a further embodiment of the invention provides a natural feeling of comfort of the air in a room, wherein, in particular, gaseous volatile hydrocarbon are removed, the oxidation potential of the air is lowered, and microorganisms are eliminated.
According to a further embodiment of the invention, a minimum intensity of oxygen ions approximately equal to 5% of the installed ionization capacity of the air treatment device is ensured. This corresponds to the natural conditions.
The ionization power of the at least one ionization apparatus is controlled such according to a further embodiment of the invention that it increases with increasing proportions of volatile hydrocarbons and/or increase of the air velocity and/or increase of the relative air humidity and/or increased proportion of oxidizable air components. This ensures that an air supply, that is substantially not loaded, is introduced into the room or the recreation zone as a result of the predetermined air exchange and the optimized ionization intensity when the air quality in the room deteriorates.
A beneficial control of the ionization apparatus is advantageously possible according to further embodiments of the invention by means of a temporally supplied periodic alternating voltage. In this connection, the ionization apparatus is loaded with alternating pulses or alternating pulses combined to packages of a periodic alternating voltage that is available. The optimized discharge voltage is constant in this connection.
According to a further embodiment of the invention, the contents of ozone is lowered such that the desired in predetermined limit values of a comfortable room climate are ensured. In a first range, the power of the ionization apparatus is lowered. When the value of the ozone contents of the supply air increases despite the lowering of air ionization, at least one external ozone source is present. In this case, an operational mode for decomposition of ozone is switched on by means of the electronic control device. When the predetermined limits are again reached, the device is switched again to normal operation. In the operational mode xe2x80x9cozone decompositionxe2x80x9d, the energy level of the ozone is changed such that it decomposes. The fixed points for signalizing certain ozone values are selected such that a sufficient response safety is present.
The presence of a continuous ionization intensity according to a further embodiment of the invention results in that the air supplied to the room is continuously affected. When sudden changes of the conditions occur, for example, by the presence of many smokers in the room or the presence of strongly acting cleaning supplies, the time constant before a reaction occurs is shortened substantially so that the room air is positively affected faster or is immediately neutralized.